You might call Under the Skin a road movie. Or a forest movie. Or even a Scotland movie. The locations aren't extravagant, but it was the task of production designer Chris Oddy to create an overwhelmingly alienating atmosphere, whether it be in a dank forest or a Glaswegian nightclub. How much production design was actually involved? "I think a lot, actually," argues Oddy, who got involved in the film at the outset 10 years ago. "All the locations are in themselves exhaustibly picked – we looked at all sorts of forest locations for the end of the film. At one point we were focussing on a loch, I think I looked at images of about 600 lochs before we zeroed in on what we were going to do."

Scarlett Johansson contemplates some cakeCourtesy of STUDIOCANAL UK

FIVE UNDER THE SKIN PRODUCTION FACTS

1 Every castle in Scotland was looked at for a scene when a castle interior was needed

2 The black world or 'void' was entirely created on a stage on a black glass floor

4 The film was shot entirely chronologically as "it was Jon’s wish to shoot chronologically through the story". It all worked to plan apart from one sequence where "Scarlett is caught and the alien is revealed towards the end of the film"

5 Due to the lack of daylight in the dense forest, about 20 of the tree tops had to be removed to allow light in for filming

ODDY ON THE BLACK 'VOID'

"That was built on stage. When the alien takes the victims into that black world, that threshold, the transitional place was a building in each case and was very heavily designed. The black world was entirely created on a stage on a black glass floor. Jon’s idea was a joining between the (alien) world and ours. The floor that they’re walking on was a complete reflection. We had a tank set in the floor of the stage surrounded by black glass and then a mechanism in the tank to lower the victim into the floor on camera. And then a system within it to counteract the overflow. Obviously if you put something in a liquid bath, you get the Archimedes effect and the liquid overflows so there was something in the tank that diminished at the same rate that the person was going in. The glasses were four metres by three so they were big pieces of glass painted black and it was a big area of eighty by sixty feet."

Mummified skinCourtesy of STUDIOCANAL UK

ODDY ON THE MUMMIFIED SKIN

"Some of the thoughts that we banded about included things like mummified remains; bog men that had been dug out of the waste. The bogs that they’ve dug mummified remains out of essentially contained whole humans that had their skin mummified, and those references played heavily in the repercussions of what happened to the humans in the alien world. Almost the consumption of them in a way, which left just the skin.

We developed the idea that the victim is in this liquid, one character meets another who’s been there for a while and they have become disgorged, bigger and bloated. It was a way of giving them a form that we could film that wasn’t a human. That’s what lead us on an evolutionary path towards skin because that became them wearing themselves effectively. So when those characters are in the liquid, they have their own skin worn on top of their own body but separate from them. Much like a human skin wet suit I suppose."

ODDY ON THE FILM'S COMPLICATIONS

"There were many. It was Jon’s wish to shoot chronologically through the story and the one section that we were unable to do that with was the section were Scarlett is caught and the alien is revealed towards the end of the film. We went into a wood that was extremely dark. To increase the amount of light in the forest, I took about twenty of the trees' tops off to let more light flood into the woodland. That meant the snow came into the forest when it snowed. If I hadn’t taken the tops of those trees down we wouldn’t have had the shooting days that we got."

ODDY ON FINDING THE RIGHT CASTLE

"I did look at every castle. Literally every castle. They sort of fall into two camps in Scotland: they’re either a castle that is pretty much a ruin or a castle that one would have a function at, which is the sort of castle we weren’t interested in. There are only so many."

ODDY ON CRUNCHING TIME

"The bothy that she sleeps in is one of 25 bothys that existed in Scotland. I looked at two or three in the flesh but I looked at photographs of all of them and their location. That one was by far and away the best, in fact it was quite close to Glasgow which was our main unit base. It was awkwardly about (and this is the main problem with Scotland) two and three quarter hours to drive around another body of water to reach it – that meant it was off the cards because we couldn’t get there in time. So what we did was put a jetty on one side of the loch and got a boat across the loch from another jetty that existed in a small town on the other side. It ferried everyone across in the morning, turning a two and a half hour journey into a 10 minute journey."

The bothy – set up for the alien's forest baseCourtesy of STUDIOCANAL UK

ODDY ON THE PAINTERLY REFERENCES

"We looked at all sorts of paintings: Bruegel, we were looking at Hieronymus Bosch a lot. We were looking at various ancient paintings, a lot of Baroque stuff and then looking at the landscape and trying to feed that back into the dereliction."

ODDY ON SEEING THE FINAL CUT

"I have a certain fascination for that side of it. I’ll enjoy watching it with the general public when it’s released, I’m keen to do that. There’s a fascination for me to do that. I’m not sure it’s particularly relevant. I think it’s a film that’s going to be quite dividing. I can’t imagine anybody having a soft reaction to this film and I think that’s a very good thing."

Under The Skin is available digitally now and on Blu-ray and DVD from July 14